Requirement:

Our answer:

This is a native Confluence feature. The software allows you to follow users and build a network and get updates from the people you follow (http://seibert.biz/confluencefollowusers). It also allows you to subscribe to pages, trees and whole spaces and blogs within the application. Confluence has a thoughtful approach to notifications both in-app as via email with digests for multiple changes (http://seibert.biz/confluenceemailnotification).